private void button1_Click(object sender, EventArgs e)
{
if (textBox1.Text.Trim().Equals("")) {
return;
}
comboBox1.Items.Add(textBox1.Text.Trim());
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
textBox1.Text = comboBox1.SelectedItem.ToString();
}